Prof. Lisandro Benedetti-Cecchi1
1Department of Biology, University of Pisa, Pisa, Italy
Ecological stability and variability are two sides of the same coin. Nature is variable and variability is the quintessence of biodiversity. Yet, understanding the processes that confer stability to biodiversity has become an urgent need to anticipate and possibly mitigate the impacts of climate change and direct human disturbances on ecosystem processes and services. A recent theoretical framework combines a common measure of stability – the inverse of the coefficient of variation – with temporal asynchrony to partition stability at multiple levels of ecological organization, from populations to metacommunities. The procedure builds on the principle of compensatory dynamics, whereby the temporal stability of an aggregated variable increases with increasing asynchrony among the constituent elements. Although employed successfully in various systems, a potential problem with this approach is that stability of the aggregated variable may not reflect stability in functional space. Temporal shifts in species composition and abundance may cause functional instabilities, while still contributing to stabilize the aggregated variable through asynchrony. I illustrate this problem with a dataset consisting of 10-yr long timeseries of rocky intertidal algae and invertebrates from 640 plots subjected to a variety of press and pulse perturbations. Results show that perturbed and unperturbed assemblages can display the same degree of stability in total abundance, while differing markedly in species composition and despite considerable loss of unique species traits following disturbance. Interpreting stability can be misleading unless there is a clear understanding of which species and functional traits contribute to stabilize the aggregated variable.
Biography:
Lisandro Benedetti-Cecchi (LBC) is Professor in Ecology at the University of Pisa. LBC’s lab uses marine coastal plants and animals as experimental model systems to address fundamental ecological questions, including the causes and consequences of loss of biodiversity and the ecological impacts of climate change. LBC has published +165 papers in peer reviewed ecological journals and 10 chapters in books. His work has been cited +11100 times and has an H-index of 59 (Google Scholar). LBC is included among the top 2% scientists worldwide in Marine Biology, based on Scopus citation metrics and has received the ITRS award in 2019.
